Charging device for metallurgical furnaces



Aug. 17, 1937. s. LONGENECKER CHARGING DEVICE FOR METALLURGICAL FURNACESFiled July 16, 1956 2 Sheets-Sheet 1 Llllllllll m A #84 ATTORNEYS.

1937- L. s. LONGENECKER I 2,090,056

CHARGING DEVICE FOR METALLURGICAL FURNACES Filed July 16, l956 2Sheets$heet 2 v INVEN TOR. I

BY $272M I @ATTORNEYS. 1

Patented. Aug. 17, 1937 CHARGING DEVICE FOR METALLURGICAL FURNACES LeviS. Longenecker, Pittsburgh, Pa.

Application July 16, 1936, Serial No. 90,926

5 Claims.

This invention relates to material handling devices and moreparticularly to machines for charging open hearth and othermetallurgical furnaces.

The practice followed in charging open hearth furnaces involves the useof relatively small charging boxes carried by the peel arm of a chargingmachine. A box is filled with a charge, steel scrap for example, pushedthrough the door of a furnace and the peel arm rotated until the box isupside down, thereby discharging the contents on the furnace hearth.Furnaces as now designed are provided with a plurality of doors locatedbetween the buck-stays in the furnace front wall. These doors are,because of the space between buckstays, relatively small and thisnecessitates the use of small charging boxes. The use of small chargingboxes entails a long charging time, a reduction in the rates of activeperiod of the furnace to charging time, and uneven distribution of thecharge over the furnace hearth.

This invention is designed to be used with open front furnaces, such asshown by my United States Letters Patent No. 2,024,649 and NaismithPatent No. 1,778,505, and accordingly may be made almost as wide as thedoor opening and of a capacity that will, in its largest size, carry anddeliver a full furnace charge in one operation. Of course, the machinemay be made smaller if desired so that a complete charge may bedelivered in two or more operations.

An object of this invention is to provide a charging machine of suchconstruction that the charge may be deposited in the furnace withoutturning the charge carrier upside down.

Another object of the invention is to provide a machine whereby thematerial may be deposited uniformly over the furnace hearth withoutpushing the material out of the charge carrier.

A further object of the invention is to provide a machine which, whenoperated to discharge material, will cause the material to fall bygravity uniformly on the furnace hearth, and to this end a charging boxis provided having a bottom which in effect is gradually pulled out fromunder the charge whereby the charge is not subject to forces tending toroll it up into balls'or to move the same violently into contact withthe furnace arch or back wall.

And a still further object of the invention is to provide a chargingmachine having a bottom so constructed that the charge will be depositedon the furnace hearth in a progressive manner from the back Wall to thefront of the furnace. 7 Other objects of the invention will, in part,

be apparent and will, in part, be obvious from the following descriptiontaken in conjunction with the accompanying drawings in which:-

Figure 1 is a view in longitudinal section of a charging device or boxdisposed in charge re- 5 ceiving position and embodying one form of theinvention;

Fig. 2 is a fragmentary view showing the box in its unloaded position;

Fig. 3 is a view in section taken on line III-III of Fig. 1;

box.

Throughout the drawings and the specification, like reference charactersindicate like parts.

The charging machine which I have chosen to illustrate in Figures 1 to4, inclusive, of the drawings, as embodying one form of the invention,comprises a main frame or supporting structure I having sides 2 and 3braced at suitable points with angle bars 3 and a charge supporting anddumping structure comprising a bottom or floor 4 and back 5 bothdisposed between sides 2 and 3 and forming therewith a box or carrierfor scrap or other material to be charged into a funace.

The charge supporting structure is supported by the main frame I, theone being movable relative to the other.

When the frame and charge supporting structure occupy the relativepositions shown in Figure 1, the machine is ready to receive andtransport material, say scrap steel, and charge the same into an openhearth furnace, or billets may be transported and charged into a heatingfurnace.

The bottom or floor 4 is constructed to be extended as in Fig. 1 when acharge is to be transported, and contracted to the position shown inFig. 2 when the charge is to be unloaded in a furnace.

The manner of accomplishing this actending beams 6 are disposed.

These beams, as

shown, may be of inverted T-shape with the flanges 1 thereof in theplane of the lower edges of sides 2 and 3.

The upper edges 8 of these beams slope downwardly from a point 9 behindback 5 to the front ends l thereof to conform to the sloping or steppedcontour of floor 4. To strengthen and rigidify the edges 8, angle bars Hare secured on each side of the webs of each beam 6. Angle bars H arealso secured to sides 2 and 3 to strengthen and rigidify them at thepoints adjacent the side edges of floor 4. The rear ends of beams 6 aretied together by means of a heavy beam [2 preferably of channel shape.

Beams 6 are further tied together by means of I-beams l3. in depth andare short, being only long enough to span the space between a pair ofbeams 6 or the space between sides 2 and 3 and the adjacent beams 6. Asmay be seen in Fig. 1, I have shown three beams I 3 disposed between andspaced lengthwise of a pair of beams 6, and the ends of these beams reston flanges 1 when they are 10- cated between a pair of beams 6, whilethe ends of the beams between the sides 2 and 3 and an adjacent beam 6,are carried by flanges I of a beam 6 and angles I4 secured to the sides2 and 3 adjacent their lower edges. Of course, the

beams above described that form the main frame structure areappropriately secured together to insure a rigid strong structure and toobtain this end any means and methods known to the art of steelfabrication would be employed.

Sides 2 and 3 and beams 6 have secured thereto channels I5 that serve assupports and tracks for floor 4, and extend, as shown in Figure 1,throughout substantially the full length of beams 6.

The floor of the charge supporting frame comprises a series of plates ato i, inclusive, disposed transversely of and above beams 6 in spacedrelation to angle bars II, and in stepped relation to each other, i. e.,the forward edge of one plate overlies the rear edge of an adjacentplate. Plate a is secured at its ends to sides 2 and 3 and to an endplate "5 which in turn extends across and is secured to the front endsof beams 6. The remaining plates 1) to i inelusive are supported attheir rear edges on support legs I! disposed in pairs between beams 6and the sides 2 and 3 and adjacent beams 6. Each pair of support legs I!has a shaft l8 journaled therein carrying wheels I9 that run in trackchannels l5. The forward edges of these plates are supported by the rearedges of adjacent plates. In order to limit the travel of axles l8 in aspreading direction, stop links 20 are employed to connect one axle tothe other.

5' Rear wall 5 is secured to the forward edge of plate i and rigidlybraced by struts 2| and 22 which are anchored to structural steel framemembers 23 supported on posts 24 having wheels 25 at their lower endsrunning in the track channels l5.

From the drawings and the above description it will be apparent that themain support frame and the charge carrying frame are movable relative toeach other and that if either is held sta- 6 tionary the other may bemoved with respect to it.

If the charging machine is in charge receiving adjustment as shown inFig. 1, is fully charged with scrap or other material, and if the 70charge is uniformly distributed over floor 4, and if it be assumed thatthe machine is suspended from a crane attached to the framework of thecharge receiving frame adjacent wall 5, then by pulling main frame lrearwardly the floor plates 75 starting with plate a will slide oneunder the These beams are relatively shallow other until they occupy therelative position shown in Fig. 2. As each plate moves under anotherplate, the charge is unloaded progressively from front to back and fallsby gravity in a uniform manner on the furnace hearth. The abovedescribed action of floor plates at to 2' takes place because the platesback of plate a are held by friction, caused by the weight of thematerial on them, against movement while plate It moves rearwardly withthe main frame. As soon as the rear edge of plate a strikes supports I!at the rear edge of plate b plates "11, and b will move rearwardlytogether and when plates 12 and b are under plate "0 and the rear edgeof plate 17 strikes the supports at the rear edge of plate c, plate dand plates a 1) start moving rearwardly, meanwhile the material whichwas carried by them will have dropped by gravity to the place intended.This action continues with movement of the main frame until the platesare in the position shown in Fig. 2.

When the charging machine has been actuated to the unloading positionindicated in Fig. 2, the machine may be extended to its loading positionby merely pushing the main frame forwardly, or by pulling the chargesupport frame rearwardly. If the first named movement is employed, itWill be seen that plate a will move forwardly a distance equal to thelength of chain or link 20 at which time plate b is pulled forwardly bya chain 28, and when plate "b has moved forwardly the length of a chain,plate 0 will be pulled forwardly, and in like manner plates (1 to 2'will be pulled forwardly to position until floor 4 is in its fullyextended position. If the second movement is employed, the reverseaction takes place, i. e., plate 2' will move rearwardly a distanceequal to a chain length and then plate h etc., until the floor is inextended position.

Relative movement between the main frame and charge carrying frame maybe accomplished in a number of ways and by various means. In Figures 1,2 and 4, I have indicated a motor driven chain and sprocket wheel drivecomprising a plurality of chains 26 extending lengthwise of the mainframe and between beams 6, idler sprockets 21 and 28 associated witheach chain, a driving sprocket 29 for each chain disposed between a pairof idler sprockets 21 and 28, a driven sprocket 38 coupled to therespective shafts 3| on which sprockets 29 are mounted. All of thedriven sprockets 36 are driven by chains 32 and sprockets 38 mounted ona shaft 34 which in turn is driven by a motor M. The idler sprocketshafts 35 and shafts 3! are carried by the framework of the chargecarrying frame between beams 6, and chains 26 are anchored at theiropposite ends in channel l2 and plate l6 respectively of the main frame.To provide a resilient drive between the machine frames, the rear endsof the chains may be connected by bolts 31 to compression springs 33,the bolts being anchored in thrust plates 39 disposed over the outerends of the springs.

In Fig. 5, different means for handling the charging machine andobtaining relative movement between the main and charge supportingframes, are illustrated. The charging device in this instance issupported on rollers R carried on a car 46 running on tracks along thefronts of furnaces, one furnace being diagrammatically illustrated at 4|carried by car 46 while being loaded with scrap or other material andtransported by the car to The charging device would be p the particularfurnace to be charged. When the charging device is in position, amachine 42 running on tracks 43 and having independently operable setsof peel arms 44 and 45, (as many as required in each set), would becoupled to main and charge supporting frames of the charging device orbox.

The peel arms 44 of one set are connected by couplings 46 to the rearend of the main frame i. e., to channel beam 12 and the peel arms 45 ofthe other set are connected by couplings 4'! to rear end of theframework associated with the charging carrying frame. In the case ofpeel arms 44, there would be one arm coupled to the main frame at eachend of beam [2, with as many intermediate arms coupled to this beam asmay be required to carry the stresses involved. Likewise, in the case ofpeel arms 45, there would be one arm coupled to the rear end of thecharge carrying frame adjacent the sides thereof and as many additionalintermediate arms as may be required to hold the charge carrying framerigidly in place while the main frame is being retracted in theunloading operation.

When the charging box is in position in front of a furnace, the peelarms are moved by mechanism not shown towards the furnace until thecharge carrying floor 4 is entirely within the furnace. When in thefurnace, peel arms 45 are held stationary and peel arms 44 are movedrearwardly whereby floor plates 0. to i are caused to move progressivelyrearwardly in the manner already described in connection with Figs. 1 to4.

When operating the charging device into or out of a furnace either by acrane as mentioned in connection with Figs. 1 to 4, or by the meansdescribed in connection with Fig. 5, it will be understood by thoseskilled in this art that the charging device will require more or lesscounterweighting to compensate for the overhanging weight of the chargeand the weight of the portion of the charging machine extending into thefurnace.

While I have described the unloading operation of the machine asinvolving movement of the main frame while the charge carrying frame isheld stationary, it will be appreciated that the unloading may beaccomplished also by moving both frames in opposite directions or I maymove the charge carrying frame and hold the main frame stationary. Thislatter movement, however, is subject to a possible disadvantage in thatsmall pieces of scrap might become wedged between the floor plates atthe places where they overlap, as the material is pushed off, whereas inthe other movement, the material is not pushed off, but drops by gravitybecause the fioor is moved out from under the material.

As various changes may be made in the details of construction or" themachine herein disclosed without departing from the spirit or scope ofthe invention. I desire that only such limitations shall be imposed asare required by the prior art and the appended claims.

What I claim as new and desire to secure by Letters Patent is:-

1. A device designed to be moved into a furnace with a charge ofmaterial to be deposited therein, comprising a main support frame, anauxiliary support frame carried by the main frame and mounted formovement relative thereto, said auxiliary support framehaving a floormade up of a plurality of members, rollers for individually supportingsaid floor members for movement on said main frame, said floor membersbeing disposed to move relatively one under the other when relativemovement between the frames is effected, and cause material carriedthereby to fall by gravity and be discharged on the floor or hearth of afurnace, and means for moving said frames relative to each other.

2. A device according to claim 1 in which the floor is made up of aplurality of substantially fiat plates, that the support rollers arepositioned under and adjacent the rear edges of said floor plates, andthat the front edges of successive plates are supported by the rear edgeof an adjacent plate so that the plates may move one under the othersuccessively and progressively from front to back as the plates aremoved from charge supporting to charge unloading position.

3. A device according to claim 1 in which the main and auxiliary framesare provided with sides and a back, respectively, forming with the floora charge carrying box and from which the charge falls by gravity as thefloor members are moved out from under the material.

4. A device according to claim 1 characterized by the fact that sidemembers are attached to the sides of the main frame, that .a back isattached tothe auxiliary frame adjacent the rear edge of the rear floormember, and that the front floor member is attached to the main frame.

5. A device according to claim 1 characterized by the fact that the rearedges of the floor members are supported on rollers, that the main frameis provided with tracks to guide and support the rollers, that theforward edges of said plates rest on the rear edge of an adjacent plateand that the front plate is connected to the main frame, whereby whenthe main frame is moved rearwardly relative to the floor, the frontfloor plate slides under the next plate until it strikes the supports ofsuch next plate causing the second plate to move rearwardly until itstrikes the supports of the third plate, such action continuing withmovement of the main frame until all the plates have moved one underanother and causing material carried by the floor to fall by gravity asthe fioor plates are pulled from under the same.

LEVI S. LONGENECKEBk

